Field of the Invention
The present invention relates to a connecting device. The invention also relates to a connector comprising such a device.
The field of the invention is that of connectors adapted for the passage of fluids under high pressures and high or very low temperatures, which require maximum safety and demand sealing using metal parts. Advantageously, such sealing is achieved by metal-on-metal contact without using a seal made from a polymer material. The invention is well suited to specific applications in the field of cryogenics.
Brief Description of the Related Art
GB-A-163,053 describes a connecting device between two tubes. A first tube is screwed into a main coupling element provided with a first frustoconical surface. The second tube is screwed into a coupling ring provided with a second frustoconical surface and mounted sliding in the main element. The device also comprises a cam lever, mounted on the coupling element the second tube is inserted into the ring. Actuating the cam lever causes the two frustoconical surfaces to come closer together, then applying contact pressure, thereby producing cone trunk-on-cone trunk sealing within the device. In practice, this sealing requires exerting high forces on the cam lever on the contact surfaces. The contacts between the cam supported by the lever and the ring to be moved are linear contacts, which poses a problem of compactness and/or strength when the materials, in particular for reasons of compatibility with certain fluids, do not have a sufficient hardness to withstand caulking.
U.S. Pat. No. 5,350,200 describes another connecting device between two tubes, provided with complementary frustoconical surfaces. The connecting device comprises two annular sleeves, each including a cavity for receiving one of the tubes. The annular sleeves also comprise complementary internal and external threads. Screwing the annular sleeves causes the two frustoconical surfaces to come closer together, then applying contact pressure, thereby producing cone trunk-on-cone trunk sealing within the device.
As a non-limiting example, very low temperature applications may use austenitic stainless steels, for example of type 316L, with high stiffness under cryogenic temperatures, but a low hardness.